Taking our findings at face value (see below), variants with non-additive effects on refractive error appeared to be scarce and our results suggested that the accuracy of a polygenic risk score for myopia is unlikely to suffer appreciably from not accounting for variants with dominant or recessive alleles (for example, the difference in performance was R2 = 6.04% vs. 6.01% when account was vs. was not taken of non-additive effects of variants in ZMAT4, RD3L and LAMA2). Here, ZMAT4 is linked to myopia.